Firing rate control for oil burners and the like



H. K. WINTERS Filed Oct. 11, 1957 INVENTOR fine/e) K I/V/NTLES 7- TOENE rs.

FIRING RATE CONTROL FOR OIL BURNERS AND THE LIKE April 4, 1961 2,978,018 I FIRING RATE CONTROL FOR 011. BURNE ANDTHELIKE Harry K. Winters, San Rafael, Calif., assignor, by mesne assignments, to Ray Oil Burner Co., San Francisco, Califi, a corporation of Nevada Filed Oct. 11, 1957,'Ser. No. 689,693

, 7 Claims. (Cl. 158-28) This invention relates to burners and particularly to nature of an explosion. It is desirable, therefore, to effect ignition at a low rate and then gradually to increase the xrate to that required. Y

It is an object of the present, invention to provide means in combination with a burner to prevent any more than a slow delivery of fuel to the burner nozzle untilignition has been effected and upon the-effect of'ignition to automatically and gradually increase the rate of fuel flow and therefore the rate of firing.

It is also an object ofthe invention to provide means of the kind describedwhich also regulates the rate of flow of air to the burner in proper proportion to the flow of oil or other fuel.

A further and import-ant object of the invention is the provision of means in a firing rate control for setting the control'in its lowfire condition automatically upon the flame at the nozzle being extinguished.

A still further object is the provision of means to establish a maximum firing rate and means to control the rate of increase of firing rate which takes place automatically.

Further and more specific objects and advantages of the invention and the, manner in which they are carried into practice is made apparent in the following specification wherein reference is made to the accompanying drawing.

Ihe drawing is a schematic view of a firing rate con-. trol mechanism embodying the present invention.

1 "In the drawing an oil burner nozzle isfschematically illustrated at 10 as surrounded by an air duct 11 through which air under pressure from any suitable source, such I as a blower, notshown, is supplied to support combustion of the fuel oil being sprayed by the nozzle. A pump 12, usually of the constant volumetype, withdraws oiljfrom a tank 13 through a pipe '14 and directs it to the nozzle r by way of a line 15. A bypass line 16 connects with the line 15 in advanceof the nozzlejand permits flow of a portion of the oil to a firing rate valve 17 which is in the form of a cylinder and has a valve element 18 urged by a spring 19'toward a closed position for controlling the flow of oil through the bypass line 16, a discharge opening 19a and by way are return line 20 back to the tank 13. It is, therefore the back pressure or resistance to flow through the bypass 16 which controls therate of flow and rate of firing at the burner nozzle. Thus when the load on the spring 19 is light, the rate of firing is low as is desirable at'the time of ignition.

The cylindrical body of the firing rate valve, 17 contains ,a, piston 21 which serves as a seat for the spring 19 and is reciprocable in the valve to vary the'loading of. the spring. A line 22 communicates between the main line 15 and the interior of the firing rate valveat a point behind the piston 21 so that oilunder pressure Fatented Apr. 4, 1961- passing through the line 22 will urge the piston toward the right as viewed in the drawing to increase the loadin g on the spring 19, thus tending to close the valve 18 and raising the back pressure in the line 16 to efiect a higher firing rate. A valve 23 in the line 22 is adjustable to control the rate of fiow through the line 22 and therefore to control the time interval required for increasing the firing rate from a minimum to a maximum value. The valve 23 is preferably of the needle type to enable a relatively slow, carefully regulated adjustment of this time period. A three-way valve schematically illustrated at 24 also controls flow through the line 22, and in the position shown, which is the position that it will occupy before and at the time of ignition of the oil, prevents flow through the line 22 toward the valve 17.

I This position of the three-way valve also forms communii 15 to the tank in the event of excessive pressure therein.

Returning now to the three-way valve 24, it is shown as having a lever 29 by means of which it may be rotated in a counter-clockwise direction ninety degrees in which position it will close communication with the line 25 and open line '22 for the flow of oil between the pipe 15 and the firing rate valve 17 as' previously described. The normal positiontof the three-way valve 24 is that shown, closing the line 22, and it may be swung to its open position' by a solenoid 30 in a circuit 31 which includes a flame monitoring device in the vicinity of the burner nozzle. Various monitoring devices suitable for this purpose are available, and for purposes of illustration a photo-sensitive cell 32 is shown in the circuit and acts, uponthe presence of a flame at the burner nozzle, to close the circuit to the solenoid 30 and open the valve 24. The parts sof'ar described are illustrated in their normal position in which the firing rate will be low.

When the pump 12 is started, the oil at the nozzle is' ignited usually by an electric spark device, not illustrated, and upon the presence of a flame, the monitoring device 32 effects opening of the valve 24 and a gradual flow of oil under pressure enters the firing rate valve 17 and urges the piston 21 slowly toward the right to load tion shown whereupon the load on the spring 19 returns the piston 21 to its retracted or normal position and the oil behind the piston flows outwardly through the 31 and is normally closed as shown. This switch may valve 24 and return lines 25 and 26 to the tank 13. A manually actuated switch 34 is provided in the circuit be opened to break the circuit and to effect reduction of the firing rate from high tolow at any time. The maximum firing rate may be established by adjusting a pair of nuts 35 on the threaded portion of a piston rod 36 which is reciprocable through a head member 37 of the firing rate valve and is connected at its inner end to the piston 21. Thenuts engage the head member 37 to limit themovement of the piston toward the right and therefore limit the load which may be imposed on the spring 19.

The ratio of air to. oil, or other fuel a burner is 1 important, and this invention provides for'the automatic decreased. This is accomplished by a throttle valve indicated at 38 in the air duct 11 which is adjustable by a lever 39 connected to one end of a lever 40 pivotally supported as at 41 and connected intermediate its ends to the terminal end of the piston rod 36. Consequently movement to the right of the piston 21 which increases the flow of oil to the burner nozzle also effects opening movement of the throttle valve 38 to increase proportionately the fiow of air.

I claim:

1. A firing rate control for burners which comprises a first conduit communicating with a burner, means for directing fuel under pressure through said conduit to the burner, a by-pass line communicating with the first conduit and including a cylinder with a piston therein, a fuel control by-pass valve in said cylinder to control flow through the by-pass line, a spring between one side of the piston and said by-pass valve biasing the valve toward closed position, a second conduit forming a connection between said first conduit and the cylinder, a valve in said second conduit, and means dependent upon the existence of a flame at the burner for opening and holding said last valve open to admit fuel to said cylinder at the opposite side of said piston, to move said piston and to increase the bias exerted by said spring on said fuel control by-pass valve to effect delivery of fuel to the burner at a high rate.

2. A firing rate control for burners which comprises a first conduit communicating with a burner, means for directing fuel under pressure through said conduit to the burner, a by-pass line communicating with the first conduit and including a cylinder with a piston therein, a fuel control by-pass valve in said cylinder to control flow through the by-pass line, a spring between one side of the piston and said by-pass valve biasing the valve toward closed position, a second conduit forming a con-- nection between said first conduit and the cylinder, 21 valve in said second conduit, and means dependent upon the existence of a flame at the burner for opening and holding said last valve open to admit fuel to said cylinder at the opposite side of said piston, to move said piston and to increase the bias exerted by said spring on said fuel control by-pass valve to effect delivery of fuel to the burner at a high rate, and a second valve in said second conduit to regulate the admission of fuel to said cylinder.

3. A firing rate control for burners which comprises a first conduit communicating with a burner, means for directing fuel under pressure through said conduit to the burner, a by-pass line communicating with the first conduit and including a cylinder with a piston therein, a fuel control by-pass valve in said cylinder to control flow through the by-pass line, a spring between one side of the piston and said by-pass valve biasing the valve toward closed position, a second conduit forming a connection between said first conduit and the cylinder, a valve in said second conduit, means dependent upon the existence of a flame at the burner for opening and holding said last valve open to admit fuel to said cylinder at the opposite side of said piston, to move said piston and to increase the bias exerted by said spring on said fuel control by-pass valve to effect delivery of fuel to the burner at a high rate and stop means associated with said piston to limit the maximum rate of fuel to the burner.

4 A firing rate control for burners which comprises a first conduit for directing fuel under pressure to a burner, a cylinder, a second conduit communicating between the first conduit and one end of the cylinder, a valve in said end of the cylinder, a spring in the cylinder urging the valve toward a closed position to control flow of fuel from the second conduit into the cylinder, a piston adjacent the opposite end of the cylinder forming a seat for said spring, a discharge opening in the cylinder between the valveand piston, and meansto admit fluid under pressure from the first conduit to the said opposite end 'of the cylinder while the burner fuel supply is initiated at a low firing rate to cause the piston to compress the spring and thereby gradually reduce the escape of fuel through said valve and discharge opening and increase the firing rate at theburner.

5. A firing rate control for burners which comprises a first conduit for directing fuel under pressure to a burner, a cylinder, a second conduit communicating between the first conduit and one end of the cylinder, a valve in said end of the cylinder, a spring in the cylinder urging the valve toward a closed position to control flow of fuel from the second conduit into the cylinder, a piston adjacent the opposite end of thecylinder forming a seat for said spring, a discharge opening in thecylinder between the valve and piston, means to admit fluid under pressure from the first conduit to the opposite end of the cylinder while the burner fuel supply is initiated at a low firing rate to cause the piston to compress the spring and thereby gradually reduce the escape of fuel through said valve and discharge opening and increase the firing rate at the burner, a normally closed valve preventing communication of pressure to said opposite end of the cylinder,

'means to open said normally closed valve, and flame monitoring means at the burner to actuate the valve opening means upon occurrence of flame at the burner.

6. A firing rate control for burners which comprises a first conduit for directing fuel under pressure to a burner, a cylinder, at second conduit communicating between the first conduit and'one end of the cylinder, a valve in said end of the cylinder, a spring in the cylinder urging the valve toward a closed position to control flow of fuel from the second conduit into the cylinder, a piston adjacent the opposite end of the cylinder forming a seat for said spring, a discharge opening in the cylinder between the valve and piston, means to admit fluid under pressure from the first conduit to the said opposite end of the cylinder While the burner fuel supply is initiated at a low firing rate to cause the piston to compress the spring and thereby gradually reduce the escape of fuel through said valve and discharge opening and increase the firing rate at the burner, a normally closed valve preventing communication of pressure to said opposite end of the cylinder, means to open said normally closed valve, flame monitoring means at the burner controlling actuation of the valve opening means to open the valve upon the occurrence of flame at the burner, and means operable independently of the flame monitoring means to efiect closing of said valve.

7. A firing rate control for burners which comprises a first conduit for directing fuel under pressure to a burner,

a" cylinder, 21 second conduit communicating between the first conduit and one end of the cylinder, a valve in said end of the cylinder, a spring in the cylinder urging the valve toward a closed position to control flow of fuel from the second conduit into the cylinder, a piston adjacent the opposite end of the cylinder forming a seat for said spring, a discharge opening in the cylinder between the valve and piston, meansto admit fluid under pressure from the first conduit to the said opposite end of the cylinder while the burner fuel supply is initiated at a low firing rate to cause the piston to compress the spring and thereby gradually reduce the'escape of fuel through said valve and discharge opening and increase the firing rate at the burner, a duct to direct air to the burner, 21 valve in said duct and connections between said piston and last named valve to control the flow of air to the burner in proportion to the delivery of fuel thereto.

References Cited in the file of this patent UNITED STATES PATENTS 2,145,404 Osborne Jan. 31, 1939 2,178,672 Perkins Nov. 7, 1939 2,364,489 Taylor Dec. '5, 1944 2,494,714 Lyman Jan. 17, 1950 2,516,062 Logan July 18, 1950 2,578,934 Ianssen Dec. 18, 1951 

